140 



og som Vogt bar kaklet „la loge dorsale impaire", der 

 støder til den lille dorsale Svælggrube, Tab. XXV, Fig. 8, 

 11 J. Om denne Del udtaler Vogt sig saaledes: „c'est 

 eette partie qui est de la phis haute importanee pour la 

 consideration morphologique du Cerianthe;'' thi derfra ei- 

 det, siger han. at ikke alene Skillevæggene og Kamrene 

 udvikle sig og stadig tihage i Ant-al; men ogsaa Tentak- 

 lernes Fremvæxt og Tihagen udgaar væsentlig derfra, et For- 

 hold, der er fuldkomment ligt det, lian har beskrevet med 

 saamegen Xoiagtighed hos Slægten Arachnactis. Dette 

 er jo en Udviklingsmaade, som er meget forskjellig fra den, 

 der tinder Sted hos Actinierne i Ahnindelighed, og ganske 

 modsat den hos Zoanthiderne, forsaavidt som hos disse, 

 ifølge Erdmanns Angivelse, de nye Septa optræde i to 

 Interseptalkamre, nemlig i hvert Sidekammer. der støder 

 til de ventrale Retningssepta. 



Hos Cerianthus Vogti har jeg ikke med fu Ul Sikker- 

 hed kunnet bekræfte Rigtigheden af Vogts Iagttagelser. da 

 jeg dertil har manglet tilstrækkeligt Materiale; men naar 

 jeg ser hen til Anordningen af Septa og Kamre hos nævnte 

 Art. saa nærer jeg ingen Tvivl om Rigtigheden. I det 

 dorsale, uparrede Kammer syntes jeg at opdage et begyn- 

 dende Septum, men jeg var ikke sikker og forblev derfor 

 staaende med at antage det for en Epithelialdannelse ; din 

 for omtalte, isolerede, dorsale Randtentakel i Forening 

 med den Orustændighed. at især Mundtentaklerne staa 

 baade meget tættere og ere tildels mindre paa Rygsiden 

 end paa Bugsiden, synes at tyde hen paa, at den af Vogt 

 omtalte Udviklingsmaade, ogsaa foregaar hos Cerianthus 

 Vogti. 



De to Septa, Tab. XXV, Fig. 8 /;. 11 g. \2 /. et 

 paa hver Side af de ventrale Retniugssepta, forlænge sig 

 ved Siden af disse nedover tien indre Kropsvæg lige til 

 den aborale Aabning. og ere blevne kaldte de ..konti- 

 nuerende Septa 1 ', Tab. XXV, Fig. 10 a. Der, hvor de 

 foroven slutte sig til Retningssepta, Tab. XXV, Fig. 10 b, 

 er en Fordybning omgiven af en halvmaaneformig Vold. 

 Tab. XXV, Fig. 10 c, og i denne Fordybning synes der 

 at være en fin Aabning udåd. Jeg angav tidligere, at de 

 to ventrale Retningssepta ere temmelig korte, men tykke; 

 naar de forlænge sig nedover, hegge de sig sammen saa- 

 ledes, at der imellem dem bliver en Rende. ligesom de 

 kontinuerende Septa omgive dem, hvorved der imellem 

 disse og Retningssepta bliver en Fure, Tab. XXV, Fig. 

 10 d. Den nysnævnte Rende. Tal). XXV, Fig. 10 p* 

 fortsættes, efterat Retningssepta ere ophørte, imellem de 

 kontinuerende Septa lige til Caudalaahningeu, og det er 

 denne Rende, der er kaldet Bugrenden. som aabner sig 

 i den ovenomtalte Grube. Tab. XXV. Fig. 10 c. 



Fortiden disse to kontinuerende Septa er der paa 

 hver Side af dem 3 — 4 Septa, som strække sig saa langt 

 ned mod Caudalaabningen, at de paa nogle Millimeter nær 

 naa denne, Tal). XXV. Fig. 8 i. Disse Septa. ligesom 



next adjoining chambers, which Vogt has termed „la loge 

 dorsale impaire-, and which adjoins the small dorsal 

 gullet-groove (Pl. XXV, fig. 8, 1 1 f). Regarding this 

 part Vogt expresses himself thus: „c'est eette partie qui 

 est de la phis haute importanee pour la consideration 

 morphologique du Cerianthe" as it is, he says. from it. that 

 not only do the divisional walls and the chambers develope 

 themselves and steadily increase in nuniher, but also the 

 development of the tentacles and their increase in number 

 principally arises ; a relation that is perfectly like what 

 he has described, vvith so much exactness, in the genus 

 Arachnactis. This is eertainly a mode of development 

 very different from that which occurs in the Actinaria in 

 general, and quite the opposite of what occurs in the 

 Zoanthidæ, in so far, that in these, aecording to Erdmann's 

 statemeht, the new septa appear in two interseptal cham- 

 bers, viz. in each lateral chamber that adjoins the ventral 

 directive septa. 



In Cerianthus Vogti I have not been able, with per- 

 fect certainty, to confirm the correetness of Vogts observa- 

 tions. as I have not bad sufficient material at my disposal 

 foi- that purpose; but when I consider the arrangement of 

 tlif septa and chambers in the species named, I can have 

 no doubt of their correetness. In the dorsal unpaired 

 chamber, I fancied I observed a rudimentary septum but 

 was not certain about it, and contented ntvself, therefqre, 

 with assumtng it to be an epithelial formation; the previ- 

 ouslv mentioned isolatet! marginal tentacle, in conjunction 

 with the circumstance that the oral tentacles. especially, 

 are placed, both much more coinpactlv. while they are 

 also partlv smaller on the dorsal side than on the ventral 

 side. appears to point to the mode of development spoken 

 ot by Vogt also occurring in Cerianthus Vogti. 



The two septa (Pl. XXV, fig. 8 //. 11 g, 12 /i. one 

 on each side of the ventral directive septa, prolong them- 

 selves on the side of these last. down along the inner 

 wall of the body quite to the aboral aperture, and have 

 been termed ..the continuing septa- (Pl. XXV. fig. 10 a). 

 At the top, where they unite to the directive septa (Pl. 

 XXV. fig. 1<> b), there is a depression surrounded by a 

 semi-liinar shaped rampart f Pl. XXV. flg. lo c), and in 

 that depression there appears to be a min ute aperture 

 outwards. I stated, previously, that the two ventral direc- 

 tive septa are rather short, but thick; when they prolong 

 themselves downwards they close together in such a man- 

 ner, that a channel becomes formed between theiu, whilst. 

 also, the continuing septa elose round them, producing, 

 thus, between them and the directive septa, a furrow (Pl. 

 XXV. fig. 10 d). The channel just mentioned (Pl. XXV. 

 fig. 10 e) is continued, atter the directive septa have 

 ceased, between the continuing septa, quite to the caudal 

 aperture. and it is this channel that opens into the cavity 

 spoken of above (Pl. XXV, fig. 10 c). 



Besides these two continuing septa there are. on 

 each side of them, 3 — 4 septa that stretch themselves so 

 far down towards the caudal aperture that they reach to 

 within a few millimetres of it iPl. XXV. fig. Si). Those 



